Buggy code:
@ JsonSerialize ( include = JsonSerialize . Inclusion . NON_NULL ) public class RequestPattern { private String urlPattern ; private String url ; private String urlPath ; private RequestMethod method ; private Map < String , ValuePattern > headerPatterns ; private Map < String , ValuePattern > queryParamPatterns ; private List < ValuePattern > bodyPatterns ; public RequestPattern ( RequestMethod method , String url , Map < String , ValuePattern > headerPatterns , Map < String , ValuePattern > queryParamPatterns ) { } public RequestPattern ( RequestMethod method , String url , Map < String , ValuePattern > headerPatterns ) { } public RequestPattern ( RequestMethod method ) { } public RequestPattern ( RequestMethod method , String url ) { } public RequestPattern ( ) { } public static RequestPattern everything ( ) { } public static RequestPattern buildRequestPatternFrom ( String json ) { } private void assertIsInValidState ( ) { } public boolean isMatchedBy ( Request request ) { } private boolean urlIsMatch ( Request request ) { } private boolean methodMatches ( Request request ) { } private boolean requiredAbsentHeadersAreNotPresentIn ( final Request request ) { } private Set < String > requiredAbsentHeaderKeys ( ) { } private boolean headersMatch ( final Request request ) { } private boolean queryParametersMatch ( Request request ) { } private boolean noHeadersAreRequiredToBePresent ( ) { } private boolean allHeaderPatternsSpecifyAbsent ( ) { } private boolean bodyMatches ( Request request ) { } public String getUrlPattern ( ) { } public void setUrlPattern ( String urlPattern ) { } public RequestMethod getMethod ( ) { } public void setMethod ( RequestMethod method ) { } public Map < String , ValuePattern > getHeaders ( ) { } public Map < String , ValuePattern > getQueryParameters ( ) { } public void setQueryParameters ( Map < String , ValuePattern > queryParamPatterns ) { } public void addHeader ( String key , ValuePattern pattern ) { } public void addQueryParam ( String key , ValuePattern valuePattern ) { } public void setHeaders ( Map < String , ValuePattern > headers ) { } public String getUrl ( ) { } public void setUrl ( String url ) { } public String getUrlPath ( ) { } public void setUrlPath ( String urlPath ) { } public List < ValuePattern > getBodyPatterns ( ) { } public void setBodyPatterns ( List < ValuePattern > bodyPatterns ) { } @ Override public int hashCode ( ) { } @ Override public boolean equals ( Object obj ) { } @ Override public String toString ( ) { } private static final Function < Map . Entry < String , ValuePattern > , String > TO_KEYS_WHERE_VALUE_ABSENT = new Function < Map . Entry < String , ValuePattern > , String > ( ) { public String apply ( Map . Entry < String , ValuePattern > input ) { } } ; private static final Predicate < String > REMOVING_NULL = new Predicate < String > ( ) { public boolean apply ( String input ) { } } ; private static Predicate < Map . Entry < String , ValuePattern > > matchHeadersIn ( final Request request ) { } private Predicate < ? super Map . Entry < String , ValuePattern > > matchQueryParametersIn ( final Request request ) { return new Predicate < Map . Entry < String , ValuePattern > > ( ) { public boolean apply ( Map . Entry < String , ValuePattern > entry ) { ValuePattern valuePattern = entry . getValue ( ) ; String key = entry . getKey ( ) ; QueryParameter queryParam = request . queryParameter ( key ) ; <START_BUG> boolean match = queryParam . hasValueMatching ( valuePattern ) ; <END_BUG> if ( ! match ) { notifier ( ) . info ( String . format ( "URL<seq2seq4repair_space>%s<seq2seq4repair_space>is<seq2seq4repair_space>match,<seq2seq4repair_space>but<seq2seq4repair_space>query<seq2seq4repair_space>parameter<seq2seq4repair_space>%s<seq2seq4repair_space>is<seq2seq4repair_space>not.<seq2seq4repair_space>For<seq2seq4repair_space>a<seq2seq4repair_space>match,<seq2seq4repair_space>value<seq2seq4repair_space>should<seq2seq4repair_space>%s" , request . getUrl ( ) , key , valuePattern . toString ( ) ) ) ; } return match ; } } ; } }

Fix:
boolean match = ( queryParam != null ) ? queryParam . hasValueMatching ( valuePattern ) : false ;